fix: Log compiler errors in js config files

[kf6kjg]

Before this change javascript config files that had compilation errors or that threw their own errors wouldn't report the error, making debugging a mite more difficult than it should be: instead you'd get a useless TypeError: Cannot read property 'errors' of undefined message. Now if the javascript config file tosses its cookies for whatever reason we can read what that reason was.

In my case specifically I was accessing a variable before declaring it. Getting

Could not parse lint-staged config.

ReferenceError: Cannot access 'result' before initialization

Please make sure you have created it correctly.
See https://github.com/okonet/lint-staged#configuration.

was a LOT more informative than

Could not parse lint-staged config.

TypeError: Cannot read property 'errors' of undefined

Please make sure you have created it correctly.
See https://github.com/okonet/lint-staged#configuration.

[iiroj]

Thanks for the PR! Unfortunately it looks like you left some unlinted code in the commit (maybe you didn't run lint-staged).

[kf6kjg]

@iiroj Sorry for the delay, fixed. I'd created the initial patch using GitHub's online interface based on a patch-package patch I'd created for one of my projects, and yes that interface doesn't run the linter!

[codecov]

Codecov Report

Merging #915 (1ef770d) into master (0ff2917) will decrease coverage by 0.16%.
The diff coverage is 93.33%.

@@             Coverage Diff             @@
##            master     #915      +/-   ##
===========================================
- Coverage   100.00%   99.83%   -0.17%     
===========================================
  Files           18       18              
  Lines          609      615       +6     
  Branches       143      148       +5     
===========================================
+ Hits           609      614       +5     
- Misses           0        1       +1     

Impacted Files	Coverage Δ
lib/index.js	98.61% <93.33%> (-1.39%)	⬇️

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[okonet]

and yes that interface doesn't run the linter!

We should ask GitHub to run pre-commit hooks even when their UI is used. That would be rad!

[kf6kjg]

@okonet Status on merge-ability?

[okonet]

I have zero time to look at. @iiroj could you review please? 🙏

[iiroj]

This PR needs additional tests before it can merged.

I took the liberty of creating a new branch with a test that covers this case:
https://github.com/okonet/lint-staged/compare/js-config-errors

@kf6kjg feel free to pick the commits into your branch.

[iiroj]

@kf6kjg thanks for the PR! I'll close this one and opened another one with your commit in it, along with tests: #935

[kf6kjg]

Thank you for the finishing touch! Good to see it completed.